We have some exciting news for all the HTML5 enthusiasts out there: true HTML5 fullscreen video playback is now possible, and we’ve built it right into our player.

Until now, the lack of true fullscreen playback has been the biggest limitation of HTML5 over Flash video. Safari already offered a basic fullscreen option for HTML5 video players, but this was via a non-customizable QuickTime view that didn’t allow the player to be branded or to feature custom controls.

This is a cutting-edge feature and we are breaking new ground by being the first video player to implement it. Right now it requires the very latest version of Safari 5.1, but Chrome and Firefox support should arrive soon1.

If you are reading through your RSS reader, please visit this web page on the browser to test it.

Click on the fullscreen button or double click on the video to enter fullscreen. Safari 5.1 required.

We’ve now enabled this feature on all instances of SublimeVideo Player. However, because this is a brand new feature that is currently only available in Safari, for now we have left the traditional full-window behavior as the default player option. If you are running Safari 5.1, simply hold down Command (Mac) or Ctrl (Windows) while clicking the player’s full-window button to enjoy true fullscreen HTML5 playback2. You can also double-click the video whilst holding the modifier key to activate fullscreen. You can test it yourself on some of our customers’ sites!

Stay tuned for more SublimeVideo news and developments.

UPDATE: October 11, 2011: We added True HTML5 fullscreen support for the upcoming Firefox 10.

The WebKit/Safari fullscreen implementation is actually based on Mozilla’s Fullscreen API Proposal, so hopefully this will soon be added to Firefox; you can add your voice and push for this feature on Firefox via this thread.

If you are a SublimeVideo customer and want to enable true fullscreen playback by default on supported browsers as we have in the video above (i.e. without needing to hold down the command/ctrl key) you can do it by adding the sv_html5_fullscreen class to your <video> elements.